A sensor apparatus has been known which measures nature or ingredients of a specimen by using a detection element, such as a surface acoustic wave element (for example, refer to Japanese Unexamined Patent Publication No. 5-240762).
For example, the sensor apparatus using the surface acoustic wave element has, on a piezoelectric substrate, a detection part to be reacted with ingredients contained in a specimen. The sensor apparatus is configured to detect the nature or ingredients of the specimen by measuring a change of a surface acoustic wave after propagating along the detection part.